The present invention resides in an elastic ring installation tool for the installation of elastic rings on brackets attached to the teeth of a patient for mounting orthodontic fixtures such as braces to the teeth of the patient. The elastic rings are attached onto a holder in the form of for example a magazine including a strip which is movably supported by a support member and are taken up one after another by an engagement device for installation of the orthodontic fixture.
Tools of this type are generally known. Such a so-called ligature dispenser instrument in the form of a pistol is for example shown in U.S. Pat. No. 7,220,121 B2. In this instrument, the ligatures or elastic rings are supported on the circumference of a circular support disc which is disposed rotatably in a cassette and from which the rings are picked up by a tubular carrier with wire-like fingers which are advanced to enter an elastic ring and take it along to pull it off the circular support disc while the fingers and, together therewith, an elastic ring is moved forward. As a result, the ring pulled off the support disc is disoriented from its position in a plane normal to the advancing wire-like fingers on which it is supported while an attachment neck by way of which the elastic ring is attached to the support disc is stretched in the axial direction of the tubular carrier. When the attachment neck finally rips, the elastic ring is no longer oriented in a plane normal to the extension of the tubular carrier as its needed for a proper installation.
It is the principal object of the present invention to provide an elastic ring installation tool with a magazine in the form of a holder for elastic mounting rings and an operating mechanism by which the elastic mounting rings are securely engaged and removed from the holder while safely remaining held by the support fingers of the ring installation tool in their desired orientation for installation on attachment brackets provided on the teeth of a patient.